Wang Qiong, Li Kaiyang, Zhang Daixi, Li Junying, Xu Guiyun, Zheng Jiangxia, Yang Ning, Qu Lujiang
Department of Animal Genetics and Breeding, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China.
PLoS One. 2015 Jul 10;10(7):e0132345. doi: 10.1371/journal.pone.0132345. eCollection 2015.
Genomic imprinting is a phenomenon characterized by parent-of-origin-specific gene expression. While widely documented in viviparous mammals and plants, imprinting in oviparous birds remains controversial. Because genomic imprinting is temporal- and tissue-specific, we investigated this phenomenon only in the brain tissues of 1-day-old chickens (Gallus gallus). We used next-generation sequencing technology to compare four transcriptomes pooled from 11 chickens, generated from reciprocally crossed families, to the DNA sequences of their parents. Candidate imprinted genes were then selected from these sequence alignments and subjected to verification experiments that excluded all but one SNP. Subsequent experiments performed with two new sets of reciprocally crossed families resulted in the exclusion of that candidate SNP as well. Attempts to find evidence of genomic imprinting from long non-coding RNAs yielded negative results. We therefore conclude that genomic imprinting is absent in the brains of 1-day-old chickens. However, due to the temporal and tissue specificity of imprinting, our results cannot be extended to all growth stages and tissue types.
基因组印记是一种以亲本来源特异性基因表达为特征的现象。虽然在胎生哺乳动物和植物中已有广泛记载,但卵生鸟类中的印记现象仍存在争议。由于基因组印记具有时间和组织特异性,我们仅在1日龄鸡(原鸡)的脑组织中研究了这一现象。我们使用下一代测序技术,将来自11只鸡的四个转录组(这些鸡来自相互杂交的家系)与它们亲本的DNA序列进行比较。然后从这些序列比对中选择候选印记基因,并进行验证实验,排除了除一个单核苷酸多态性(SNP)之外的所有其他SNP。随后用另外两组相互杂交的家系进行的实验也排除了该候选SNP。从长链非编码RNA中寻找基因组印记证据的尝试也得到了阴性结果。因此,我们得出结论,1日龄鸡的脑组织中不存在基因组印记。然而,由于印记的时间和组织特异性,我们的结果不能推广到所有生长阶段和组织类型。